I commend your choice of that type handgun for your wife.
I've had a Security Sis for 25 or so years now. I found the original wood grips too small for my tastes, especially with heavy loads. I put a set of rubber grips on and took them off to get the part number for you because I just knew they were Pachmayr, but alas all they say inside are "Ruger Security Six" and "Made in Italy".
Anyhow, they're thin, comfortable grips-
A little food for thought-
You might want to stick with "not so heavy" loads for her. You being a handloader gives you almost limitless options. A cast SWC around 160-170 gr. running 1000 fps would probably do fine. I routinely romp the creek bottoms near my house with a .357 carrying such loads. When I was a teenager we always had a couple dozen hogs, mostly brood sows and one or two boars, and I fed and cared for them and farrowed the sows. I've also hunted wild hogs for 30+ years. I can tell you that I was in far greater danger from our pen raised hogs than their wild brethren, the latter of which, even sows with babies, want nothing to do with homo sapiens.
As I mentioned, the Security Six, I think, is great choice for a woman. However it is a chunky revolver. If she can't handle it or you can't find grips to suit her, you might want to consider something along the lines of a Model 10. They're a little trimmer and lighter and have grips that are pretty nice for women shooters. I have three of them and my favorite, a somewhat battered police turn-in, has grips whose corners are worn smooth making it fit the palm of ones hand perfectly.
Whenever my wife, daughter or daughter-in-law want to shoot a handgun, this is the one I grab. As an added bonus, these revolvers will handle +P loads so a handloader can get a heavy-ish bullet up close to 1,000 fps.